A. Field of the Invention
The present invention pertains generally to methods and devices for aiding perception of people with low vision and more particularly to electronic devices that are capable of panning and zooming.
B. Description of the Background
Perception of objects, and particularly documents with printed matter, by people having low vision can be aided by providing displays that increase the size of the perceived object. For example, Innoventions, Inc. of Littleton, Colo., provides a hand held small aperture camera device that has a long depth of field that can be used to image printed documents and display those documents on a standard television display as disclosed in U.S. Pat. No. 5,325,123 issued Jun. 28, 1994 and U.S. Pat. No. 5,461,416 issued Oct. 24, 1995. These devices have been very useful in assisting individuals that have low vision in reading documents, especially documents with very small print. The user can adjust the magnification by changing the distance between the object being imaged and the hand held small aperture camera device without the necessity of adjusting the focus of the camera. It would be desirable, however, to be able to utilize this device for writing as well as for reading. Also, it would be advantageous to have a device that is capable of allowing the user to scan across a document while maintaining a predetermined distance from the document. Further, reading devices such as this require physical movement of either the camera or the document to scan text on the document. It would therefore be advantageous to provide a device that allows a user to electronically pan across a document and electronically adjust the magnification of the resultant image without the necessity of physically moving the document or the camera.
Various other devices exist for aiding people having low vision in various tasks, such as visual recognition at both short and long range. For example, many people having low vision use aspheric magnifying lenses to read print that is otherwise indiscernible to them. Aspheric magnifying lenses have the advantage of being very portable. They are, however, somewhat difficult to learn to use and provide a limited amount of magnification. To increase the magnification of the aspheric portable magnifying lenses, the radius of the lens must become shorter. For magnifications greater than approximately ten, these types of magnifying lenses become impractical.
Portable low vision devices have also been developed that utilize video camera technology. Devices such as these have used stationary mounted cameras that are mounted on a fixture that is worn on the user""s head such as a helmet. Such devices, however, have not been successful products for use as portable low vision aids for various reasons. Such devices tend to be very bulky requiring the use of a helmet or other fixtures that are unsightly to wear. Although such devices are capable of providing an enlarged image, usually that image is a fixed image since the camera is mounted in a fixed position on the user""s head mounted fixture. As such, the user must move their head to be able to adjust the viewing direction. For these reasons, users consider these types of devices cumbersome and unwieldy and such devices have not been readily accepted for use by people with low vision. It would therefore be advantageous to provide a portable low vision aid that is not bulky or unsightly and allows the user to adjust both the magnification and viewing angle of the user without requiring the user to turn his or her head.
Telescopes have also been used to aid people having low vision. Standard optical telescopes, however, are difficult to use and normally provide a narrow viewing angle. Stabilization of the image at narrow viewing angles is difficult and limits the use of these devices. It would therefore advantageous to also provide a device that is capable of providing an image having a wide field of view and that is capable of providing varying degrees of magnification for viewing objects at both close and far distances without the need for expensive or complex focusing techniques.
The present invention overcomes the disadvantages and limitations of the prior art by providing various embodiments for aiding individuals with low vision. In one embodiment, the present invention allows a long depth of field imaging device to be mounted on a stand to allow the user to employ the long depth of field device for aiding the user in reading and writing. In another embodiment, the present invention provides a device that employs a stationary mounted camera to view a document and allows the user to pan across the document and zoom to different magnification levels using either automated or manual controls. In accordance with another embodiment, the present invention provides a portable device that uses a camera and display optics that are mounted on a conventional type of eyewear that allows the user to pan across the field of view of the image and to adjust the zoom or magnification of the device using a manual control mechanism. A further embodiment of the present invention provides an electronic telescope/microscope (scope) that is capable of providing a bright high contrast image with variable magnification that does not require complex focusing techniques.
The present invention may therefore comprise a method of generating a magnified image of a document that has a selectable magnification and electronically panning the image to assist a user in reading the document comprising the steps of mounting a camera in a position to generate an image of the document; selecting portions of the image at different locations within the image to pan across the image; selecting the portions of the image such that the portions have different sizes that determine the selectable magnification; supplying missing pixels for the portions of the image; displaying the magnified image for reading by the user.
The present invention may further comprise a method of viewing objects with an electronic scope comprising the steps of providing a detector matrix on a first end of a housing of the scope; focusing an image on the detector matrix; selecting a portion of the image using a zoom controller; displaying the portion of the image as a full image on a display located on a second end of the scope; supplying missing pixels of the full image.
The present invention may further comprise a portable viewing device that generates an enlarged image comprising eyewear adapted to be worn over the eyes of a user; a camera mounted on the eyewear that captures an image; displays mounted in the eyewear adjacent the eyes of the user for producing the enlarged image; a controller that generates control signals relating to panning and magnification of the image captured by the camera; an interface connected to the controller and the displays that selects specific portions of the image captured in response to the control signals to pan the image captured by the camera and to display the enlarged image on the displays with different magnitudes of magnification.
The present invention may further comprise a method of generating an enlarged image in a portable viewing device comprising the steps of capturing an image generated by a detector that is mounted on eyewear that is adapted to be worn by a user; selecting portions of the image captured by the detector in response to control signals generated by a controller to produce a full image display signal that has a magnification that is proportional to the size of the portions of the image selected by the control signals and has a panning location that corresponds to the location of the portions in the image captured by the detector; displaying the full image display signal or displays mounted on the eyewear adjacent to the eyes of the user.
The present invention may further comprise a method of maintaining a substantially constant height of a small aperture camera that is scanned across a document comprising the steps of attaching a mounting plate to the camera; pivotally attaching two arms to the mounting plate with hinges that provide sufficient friction to support the camera such that the two arms cross and overlap; attaching rollers to the two arms to allow the arms to roll across the document.
The present invention may further comprise a support for a small aperture camera that allows the small aperture camera to be moved across a document at a substantially constant height comprising a mounting plate that is adapted to be attached to the camera; a pair of hinges attached to the mounting plate that provide sufficient friction to support the camera; a pair of arms attached to the hinges in an overlapping crossed relationship; a pair of rollers attached to the arms that allow the camera to roll across the document at a substantially constant height.
The advantages of the present invention are that a small aperture camera can be used having a long depth of field that is also capable of electronic panning and zooming of an object without the need to physically move the camera or object, or provide additional focusing. Either manual or automated procedures for panning and zooming can be employed. Further, these concepts can be employed in a portable device that is worn like a pair of glasses for allowing the user to perceive an enlarged image which can be electronically panned and zoomed. This eliminates the necessity for awkward movements by the user to direct the camera in a direction for viewing and provides for an aesthetic device that can be easily and worn and used. Additionally, the present invention can be embodied in an electronic scope that allows the user to view objects at both long and close distances with variable magnification and without the need to adjust the focus of the device. As such, it provides a handy portable device that is easy to use.